The buck converter of nPM1100 is designed to operate with an inductor with 2.2 µH nominal inductance, with up to ± 20% tolerance.
To ensure loop stability, do not use inductors with other nominal inductances. Additionally, the saturation current of the inductor should be greater than 300 mA. Even if the load current range required in the application under design is lower than the maximum load current of the buck converter, the saturation current requirement of the inductor should be respected. This is because the inductor peak current level is higher than the load current, especially when the buck converter operates in hysteretic mode.
The choice of inductor has a significant effect on the performance of the buck converter, especially on efficiency. The choice is typically a trade-off between size, performance, and cost. The Direct Current Resistance (DCR) given by the manufacturer is one key indicator of the performance, but as the losses in the inductor also include various frequency-dependent effects like magnetic hysteresis losses, eddy currents, and skin effect, the DCR is not a definitive performance metric.
See the following tables for examples of inductor models selected for area, performance, and cost-optimized applications.
| Manufacturer | Model | Size (inch/metric) | Height (mm) | DCR (mΩ) | Comment |
|---|---|---|---|---|---|
| Taiyo Yuden | MBKK1608T2R2M | 0603/1608 | 1 | 300 | Small footprint |
| Murata | DFE201210U-2R2M | 0805/2012 | 1 | 228 | Good performance |
| Samsung Electro-Mechanics | CIGT201610EH2R2MNE | 0806/2016 | 1 | 73 | Good performance |
| Samsung Electro-Mechanics | CIGT252008LM2R2MNE | 1008/2520 | 0.8 | 73 | Good performance, inexpensive |
| Manufacturer | Model | Size (metric) | PWM efficiency at 150 mA | Hysteretic efficiency at 1 mA |
|---|---|---|---|---|
| Murata | DFE201210U-2R2M | 2012 | 91.017 | 91.358 |
| Samsung | CIGT201610EH2R2MNE | 2016 | 91.29 | 91.218 |
| Samsung | CIGT252008LM2R2MNE | 2520 | 91.158 | 90.663 |
| TDK | VLS201610HBX-2R2M-1 | 2016 | 91.068 | 90.646 |
| Taiyo Yuden | MDKK1616T2R2MM | 1616 | 90.677 | 90.583 |
| TDK | TFM201610ALMA2R2MTAA | 2016 | 90.924 | 90.513 |
| TDK | MLP2016H2R2MT | 2016 | 91.139 | 90.392 |
| Wurth | 74479275222 | 2012 | 90.793 | 90.336 |
| TDK | MLP2012V2R2MT0S1 | 2012 | 90.613 | 90.096 |
| TDK | MLZ2012M2R2HT000 | 2012 | 91.137 | 90.053 |
| TDK | MLP2012H2R2MT0S1 | 2012 | 90.916 | 89.848 |
| TDK | MLP2012S2R2MT0S1 | 2012 | 90.339 | 89.726 |
| Taiyo Yuden | MBKK1608T2R2M | 1608 | 89.615 | 88.775 |
| Murata | LQM21PN2R2MCAD | 2012 | 90.384 | 88.719 |
| Murata | LQM21PN2R2MEHD | 2012 | 90.311 | 88.561 |
| Murata | LQM18PN2R2MGHD | 1608 | 90.096 | 87.98 |
| TDK | MLZ2012A2R2WT000 | 2012 | 89.903 | 87.725 |
| Wurth | 74479763222 | 1608 | 89.369 | 87.531 |
| Murata | LQM18PN2R2MDHD | 1608 | 88.9 | 86.43 |
| TDK | MLZ1608A2R2WT000 | 1608 | 87.797 | 86.132 |
| Murata | LQM18PN2R2NC0L | 1608 | 87.17 | 86.011 |
| Murata | LQM21PN2R2MC0D | 2012 | 88.092 | 85.46 |
| Taiyo Yuden | BRL1608T2R2M | 1608 | 87.135 | 84.584 |